Refrigerator and operation control method thereof

ABSTRACT

Disclosed herein is a refrigerator. In a refrigeration cycle including a channel switching valve to selectively supply a refrigerant to a first evaporator side and/or a second evaporator side and hot pipes, a hot pipe on a freezing chamber side and a hot pipe on a refrigerating chamber are disposed upstream and downstream of the channel switching valve, respectively to reduce unbalance in amounts of the refrigerant and in the amounts of generated heat.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2009-0129106, filed on Dec. 22, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments discussed herein relate to a refrigerator having a refrigeration cycle including evaporators provided respectively in a refrigerating chamber and a freezing chamber and an operation control method thereof.

2. Description of the Related Art

Generally, a refrigerator is an apparatus that supplies low-temperature cool air into a storage chamber to store food in the storage chamber at low temperature in a fresh state. The refrigerator may include a freezing chamber to store food at below freezing temperature and a refrigerating chamber to store food at a temperature slightly higher than freezing temperature.

Cool air to be supplied into the refrigerator is generated through heat exchange of a refrigerant. A refrigeration cycle of compression, condensation, expansion, and evaporation is repetitively performed to continuously supply cool air into the refrigerator. The supplied cool air is uniformly diffused in the refrigerator by convection to store or keep food in the refrigerator at a predetermined temperature.

A refrigerator is disclosed in which a refrigeration cycle includes evaporators provided respectively in a refrigerating chamber and a freezing chamber and a three-way valve to supply a refrigerant discharged from a condenser to the evaporator on the refrigerating chamber side or the evaporator on the freezing chamber side, thereby controlling flow of the refrigerant according to an operation mode of the refrigerator.

When cool air inside the refrigerator and hot air outside the refrigerator directly/indirectly contact each other, dew may be formed in the perimeters of openings of the refrigerating chamber and the freezing chamber due to a temperature difference. A refrigerator is also disclosed in which a hot pipe extending from the condenser of the refrigeration cycle is arranged in the perimeters of the openings of the refrigerating chamber and the freezing chamber to prevent dew formation.

The hot pipe is a refrigerant pipe mounted at a high-pressure side. Generally, the hot pipe is arranged upstream of the three-way valve throughout the perimeters of the openings of the refrigerating chamber and the freezing chamber to prevent dew formation at the openings of the refrigerating chamber and the freezing chamber through dissipation of heat from a high-temperature refrigerant gas during the operation of a compressor.

In the refrigeration cycle including the hot pipe, energy loss may occur due to unbalance in the amounts of heat generated from the hot pipe on the freezing chamber side and the hot pipe on the refrigerating chamber side and unbalance in the amount of the refrigerant.

SUMMARY

It is an aspect of the embodiments to provide a refrigerator that reduces unbalance in the amount of a refrigerant according to an operation mode of a refrigeration cycle, thereby improving cooling efficiency of a refrigerating chamber and a freezing chamber.

It is another aspect to provide a refrigerator that reduces unbalance in the amount of heat generated from a hot pipe, thereby reducing power consumption.

Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the embodiments.

In accordance with one aspect, a refrigerator includes a compressor, a condenser, a hot pipe, a first circulation channel to cool a refrigerating chamber, a second circulation channel to cool a freezing chamber, and a channel switching valve to perform switching between the circulation channels, wherein the hot pipe includes a first hot pipe on a freezing chamber side and a second hot pipe on a refrigerating chamber side, a first end of the first hot pipe is connected to the condenser and a second end of the first hot pipe an inlet of the channel switching valve, and the second hot pipe is connected to an outlet of the channel switching valve.

The second circulation channel may be connected to another outlet of the channel switching valve, and the second circulation channel may be connected to the compressor via a second expansion device and a second evaporator on the freezing chamber side.

The first circulation channel may be connected to a second evaporator on the freezing chamber side and the compressor via the second hot pipe, a first expansion device, a first evaporator on the refrigerating chamber side, and a third expansion device in a series.

The first circulation channel may be connected to a first evaporator on the refrigerating chamber side and the compressor via the second hot pipe and a first expansion device.

The channel switching valve may include a three-way valve having one inlet connected to an outlet of the first hot pipe and two outlets connected respectively to the first circulation channel and the second circulation channel.

In accordance with another aspect, a refrigerator includes a compressor, a condenser, a first hot pipe on a freezing chamber side and a second hot pipe on a refrigerating chamber site, and a controller to control a first operation mode to cool a refrigerating chamber and a second operation mode to cool a freezing chamber, wherein the controller controls a refrigerant channel such that a refrigerant discharged from the condenser cools the freezing chamber via the first hot pipe and the second hot pipe returns to the compressor during an operation in the first operation mode.

The controller may control a refrigerant channel such that the refrigerant flows to the first hot pipe during an operation in the second operation mode.

The controller may control a refrigerant channel such that the refrigerant discharged from the condenser cools the refrigerating chamber and the freezing chamber via the first hot pipe and the second hot pipe and returns to the compressor during an operation in the first operation mode.

The controller may control a refrigerant channel such that the refrigerant discharged from the condenser cools the refrigerating chamber via the first hot pipe and the second hot pipe and returns to the compressor during an operation in the first operation mode.

In accordance with a further aspect, an operation control method of a refrigerator including a compressor, a condenser, a first hot pipe on a freezing chamber side, a second hot pipe on a refrigerating chamber side, a refrigerating chamber, and a freezing chamber includes determining whether the refrigerating chamber or the freezing chamber is to be cooled and controlling a refrigerant discharged from the condenser to cool the freezing chamber via the first hot pipe upon determining that the freezing chamber is to be cooled.

The operation control method may further include controlling the refrigerant discharged from the condenser to cool the refrigerating chamber via the first hot pipe and the second hot pipe upon determining that the refrigerating chamber is to be cooled.

The operation control method may further include controlling the refrigerant to cool the freezing chamber, after cooling the refrigerating chamber, and return to the compressor.

The operation control method may further include controlling the refrigerant to return to the compressor after cooling the refrigerating chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic perspective view illustrating a refrigeration cycle of a refrigerator according to an embodiment;

FIG. 2 is a view illustrating a first operation mode of a refrigeration cycle according to an embodiment;

FIG. 3 is a view illustrating a second operation mode of the refrigeration cycle of FIG. 2;

FIG. 4 is a view illustrating a first operation mode of a refrigeration cycle according to another embodiment; and

FIG. 5 is a view illustrating a second operation mode of the refrigeration cycle of FIG. 4.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

Referring to FIG. 1, a refrigerator according to an embodiment may include a refrigerator body 10 and a plurality of storage chambers 12 and 13 partitioned by a partition 11.

The storage chambers 12 and 13 include a refrigerating chamber 12 to store food at a temperature slightly higher than freezing temperature and a freezing chamber 13 to store food at below freezing temperature. In the storage chambers 12 and 13 may be respectively provided evaporators 28 and 29 to perform heat exchange with air in the storage chambers 12 and 13.

The evaporators 28 and 29 include a first evaporator 28 mounted in the refrigerating chamber 12 and a second evaporator 29 mounted in the freezing chamber 13, respectively. The evaporators 28 and 29 are connected to a refrigeration cycle to cool the respective storage chambers 12 and 13.

The refrigeration cycle includes a compressor 21 to compress a gas refrigerant into a high-temperature and high-pressure state, a condenser 22 to condense the gas refrigerant compressed by the compressor 21 into a liquid state, expansion devices 24 and 25 (see FIG. 2) to convert the liquid refrigerant into a low-temperature and low-pressure state, and evaporators 28 and 29 to evaporate the low-temperature and low-pressure liquid refrigerant to generate cool air. These are connected to one another via a refrigerant pipe 30 such that the refrigerant is circulated while the phase of the refrigerant is changed.

The expansion devices 24 and 25 may include capillary tubes or expansion valves. The evaporators 28 and 29 may be provided in the respective storage chambers 12 and 13.

Also, the refrigeration cycle may further include a dryer 26 provided between the compressor 22 and the expansion devices 24 and 25 to remove moisture from the refrigerant supplied from the condenser 22 and an accumulator 27 provided between the evaporators 28 and 29 and the compressor 21 to restrain the supply of the liquid refrigerant to the condenser 21.

In the refrigerant pipe 30 connected between the condenser 22 and the expansion devices 24 and 25 may provided a cluster pipe 31 arranged at the top and opposite sidewalls of the refrigerator body 10 in a serpentine fashion and hot pipes 32 and 33 arranged along the perimeter of a front opening of the refrigerator body 10.

The hot pipes 32 and 33 extend from the condenser 22 such that the hot pipes 32 and 33 are buried along the perimeter of the opening of the refrigerator body 10. Formation of dew at the front of the refrigerator body 10 due to a temperature difference between the inside and outside of the refrigerator body 10 is prevented, and the amount of heat dissipated from the high-pressure side is increased, by the dissipation of heat from the high-temperature refrigerant flowing in the hot pipes 32 and 22.

The hot pipes 32 and 33 may include, a first hot pipe 32 buried in the perimeter of the refrigerator body 10 constituting the freezing chamber 13 and a second hot pipe 33 buried in the perimeter of the refrigerator body 10 constituting the refrigerating chamber 12.

Generally, a hot pipe is connected to a refrigerant pipe. The inlet and outlet of the hot pipe are connected respectively to the outlet of a high-pressure side refrigerant pipe and the inlet of a valve to control the flow of a refrigerant to a refrigerating chamber or freezing chamber evaporator.

In this case, a high-temperature refrigerant always flows in the hot pipe during the operation of a compressor, with the result that the amount of heat generated from a hot pipe on the refrigerating chamber side, the temperature of which is relatively low, is excessive, thereby lowering energy efficiency.

In this embodiment, therefore, a channel switching valve may be provided on a refrigerant circulation channel on the second hot pipe inlet side buried in the perimeter of the opening of the refrigerator body constituting the refrigerating chamber 12 to prevent lowering of energy efficiency of the refrigerator due to excessive heat generation from the hot pipe.

Hereinafter, the refrigerant circulation channel of the refrigeration cycle will be described. FIG. 2 is a schematic view illustrating the construction of a refrigeration cycle 20 according to an embodiment. In this embodiment, the refrigeration cycle is configured such that a first evaporator to generate cool air for the refrigerating chamber and a second evaporator to generate cool air for the freezing chamber are connected in series.

As shown in FIG. 2, the refrigeration cycle 20 is configured such that a condenser 22 is connected to a high-pressure side discharge port of a compressor 21, and a first hot pipe 32 buried in the perimeter of the opening of the freezing chamber 13 in FIG. 1 is connected to the outlet of the condenser 22.

A channel switching valve 34 is connected to the outlet of the first hot pipe 32. The channel switching valve 34 may include a three-way valve having one inlet and two outlets. The outlets of the channel switching valve 34 may be connected respectively to a first circulation channel 35 and a second circulation channel 36.

The channel switching valve 34 is not particularly restricted as long as one of the outlets is selectively opened, or bidirectional opening and closing is performed.

A second hot pipe 33 buried in the perimeter of the opening of the refrigerating chamber 12 is connected to the outlet of the channel switching valve 34 connected to the first circulation channel 35. A first expansion device 24 for the refrigerating chamber and a first evaporator 28 are sequentially connected to the outlet of the second hot pipe 33.

A second expansion device 25 for the freezing chamber and a second evaporator 29 are sequentially connected to the outlet of the channel switching valve 34 connected to the second circulation channel 36. The outlet of the second evaporator 29 is connected to the compressor 21 via a suction pipe 37.

Also, the outlet of the first evaporator 28 and the inlet of the second evaporator 29 are connected in series via a connection refrigerant pipe 38. A third expansion device 39 is mounted on the connection refrigerant pipe 38.

Hereinafter, the operation of the refrigeration cycle of FIG. 2 will be described.

In this embodiment, the refrigeration cycle may include a first operation mode to simultaneously cool the refrigerating chamber 12 and the freezing chamber 13, a second operation mode to cool the freezing chamber 13 alone, and a controller 100 to control the first operation mode and the second operation mode.

The controller 100 may be a microprocessor or microcontroller including a central processing unit (CPU) to perform at least one computer command to control operations of the respective components of the refrigerator according to manipulation set by a user or a predetermined program.

In the first operation mode as shown in FIG. 2, a refrigerant, compressed by and discharged from the compressor 21, is introduced into the condenser 22. The refrigerant, condensed by the condenser 22, flows to the channel switching valve 34 via the first hot pipe 32.

At this time, the channel switching valve 34 opens only the first circulation channel 35 under the control of the controller 100. Consequently, the refrigerant, introduced into the channel switching valve 34, is introduced into the first evaporator 28 via the second hot pipe 33 and the first expansion device 24 to cool the refrigerating chamber 12.

The refrigerant, discharged from the first evaporator 28, is introduced into the second evaporator 29 via the third expansion device 39 to cool the freezing chamber 13. The refrigerant, discharged from the second evaporator 29, returns to the compressor 21 via the suction pipe 37.

In the second operation mode as shown in FIG. 3, a refrigerant, compressed by and discharged from the compressor 21, is introduced into the condenser 22. The refrigerant, condensed by the condenser 22, flows to the channel switching valve 34 via the first hot pipe 32.

At this time, the channel switching valve 34 opens only the second circulation channel 36 under the control of the controller 100. Consequently, the refrigerant, introduced into the channel switching valve 34, cools the freezing chamber 13 via the second expansion device 25 and the second evaporator 29. The refrigerant, discharged from the second evaporator 29, returns to the compressor 21 via the suction pipe 37.

That is, the controller 100 determines whether the refrigerating chamber 12 or the freezing chamber 13 is to be cooled. Upon determining that the freezing chamber 13 is to be cooled, the controller 100 controls the second circulation channel 36 of the channel switching valve 34 such that the refrigerant discharged from the condenser 22 cools the freezing chamber 13 via the first hot pipe 32. Upon determining that the refrigerating chamber 12 is to be cooled, the controller 100 controls the first circulation channel 35 of the channel switching valve 34 such that the refrigerant discharged from the condenser 22 cools the refrigerating chamber 12 via the first hot pipe 32 and the second hot pipe 33.

Meanwhile, the amount of a refrigerant optimally filled in the refrigeration cycle may be changed depending upon a refrigerating operation or a freezing operation. Generally, an amount of a refrigerant between optimal amounts of a refrigerant for the refrigerating and freezing operations is filled in the refrigeration cycle.

As a result, the refrigerant is excessive in one of the refrigerating and freezing operations and is insufficient in the other of the refrigerating and freezing operations.

That is, the refrigerant is excessive in the refrigerating operation, and the refrigerant is insufficient in the freezing operation, with the result that energy loss may occur due to unbalance in the amount of the refrigerant. In this embodiment, such energy loss may be minimized.

Referring to FIG. 2, in the first operation mode of the refrigeration cycle, a larger amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the first evaporator 28 is filled. At this time, the refrigerant flows to the second hot pipe 33, thereby preventing the refrigerant from being excessively introduced into the first evaporator 28.

Referring to FIG. 3, in the second operation mode of the refrigeration cycle, a smaller amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the second evaporator 29 is filled. At this time, the refrigerant does not flow to the second hot pipe 33, thereby preventing the refrigerant from being insufficiently introduced into the second evaporator 29.

Consequently, in a conventional structure in which the refrigerant flows to both the first hot pipe 32 and the second hot pipe 33 during the operation of the compressor 21, energy efficiency is lowered due to unbalance in the amount of the refrigerant. In this embodiment, the unbalance in the amount of the refrigerant is relatively reduced, thereby improving energy efficiency of the refrigerator.

Also, since the amount of heat to be provided to prevent dew formation is generally calculated based on the first hot pipe 32 on the freezing chamber side, heat is excessively generated from the second hot pipe 33 on the refrigerating chamber side, thereby excessively increasing thermal load of the refrigerator. In this embodiment, the amount of heat generated from the second hot pipe 33 of the refrigeration cycle is relatively reduced as compared with the amount of heat generated from the first hot pipe 32, with the result that increase of thermal load due to excessive generation of heat is prevented, thereby improving energy efficiency of the refrigerator.

FIG. 4 is a schematic view illustrating the construction of a refrigeration cycle 40 according to another embodiment.

Hereinafter, components of this embodiment identical to those of the previous embodiment are denoted by the same reference numerals, and a detailed description thereof will not be given.

In this embodiment, the refrigeration cycle is configured such that a first evaporator to generate cool air for the refrigerating chamber and a second evaporator to generate cool air for the freezing chamber are connected in parallel, unlike the previous embodiment.

As shown in FIG. 4, the refrigeration cycle 40 is configured such that a condenser 22 is connected to a high-pressure side discharge port of a compressor 21, and a first hot pipe 32 buried in the perimeter of the opening of the freezing chamber 13 in FIG. 1 is connected to the outlet of the condenser 22.

A channel switching valve 34 is connected to the outlet of the first hot pipe 32. The channel switching valve 34 may include a three-way valve having one inlet and two outlets. The outlets of the channel switching valve 34 may be connected respectively to a first circulation channel 41 on the refrigerating chamber side and a second circulation channel 42 on the freezing chamber side.

A second hot pipe 33 buried in the perimeter of the opening of the refrigerating chamber 12 is connected to the outlet of the channel switching valve 34 connected to the first circulation channel 41. A first expansion device 24 for the refrigerating chamber and a first evaporator 28 are sequentially connected to the outlet of the second hot pipe 33.

Referring to FIG. 4, the second hot pipe 33, the first expansion device 24, the first evaporator 28, and a suction pipe 37 are sequentially connected to the outlet of the channel switching valve 34 connected to the first circulation channel 41. A second expansion device 25, a second evaporator 29, and the suction pipe 37 are sequentially connected to the outlet of the channel switching valve 34 connected to the second circulation channel 42.

The outlet of the first evaporator 28 is connected to a first discharge refrigerant pipe 43, which is a discharge channel of the refrigerating chamber 12. The outlet of the second evaporator 29 is connected to a second discharge refrigerant pipe 44, which is a discharge channel of the freezing chamber 13.

A refrigerant discharged from the first discharge refrigerant pipe 43 and a refrigerant discharged from the second discharge refrigerant pipe 44 are mixed before introduction thereof into the compressor 21. The joint between the first discharge refrigerant pipe 43 and the second discharge refrigerant pipe 44 is connected to the inlet of the compressor 21 via the suction pipe 37.

A check valve 45 is mounted on the second discharge refrigerant pipe 44 is mounted to prevent backward flow of the refrigerant from the first discharge refrigerant pipe 43.

Hereinafter, the operation of the refrigeration cycle of FIG. 4 will be described.

In this embodiment, the refrigeration cycle may include a first operation mode to operate the refrigerating chamber 12, a second operation mode to operate the freezing chamber 13, and a controller to control the first operation mode and the second operation mode.

In the first operation mode as shown in FIG. 4, a refrigerant, compressed by and discharged from the compressor 21, is introduced into the condenser 22. The refrigerant, condensed by the condenser 22, flows to the channel switching valve 34 via the first hot pipe 32.

At this time, the channel switching valve 34 opens only the first circulation channel 41 under the control of the controller. Consequently, the refrigerant, introduced into the channel switching valve 34, sequentially flows through the second hot pipe 33, the first expansion device 24, and the first evaporator 28, and returns to the compressor via the suction pipe 37.

In the refrigeration cycle in which a larger amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the first evaporator 28 is filled, therefore, the refrigerant flows to the second hot pipe 33, thereby preventing the refrigerant from being excessively introduced into the first evaporator 28.

Also, the amount of heat generated from the second hot pipe 33 is relatively reduced as compared with the amount of heat generated from the first hot pipe 32, with the result that increase of thermal load due to excessive generation of heat from the second hot pipe 33 is prevented.

In the second operation mode as shown in FIG. 5, a refrigerant, compressed by and discharged from the compressor 21, is introduced into the condenser 22. The refrigerant, condensed by the condenser 22, flows to the channel switching valve 34 via the first hot pipe 32.

At this time, the channel switching valve 34 opens only the second circulation channel 42 under the control of the controller. Consequently, the refrigerant, introduced into the channel switching valve 34 sequentially flows through the second expansion device 25 and the second evaporator 29, and returns to the compressor 21 via the suction pipe 37.

In the refrigeration cycle in which a smaller amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the second evaporator 29 is filled, therefore, the refrigerant does not flow to the second hot pipe 33, thereby preventing the refrigerant from being insufficiently introduced into the second evaporator 29.

In the refrigeration cycle having the coolant circulation channel as described above, therefore, unbalance in the amount of the refrigerant and unbalance in the amounts of heat generated from the hot pipes 32 and 33 depending upon the operation modes are reduced, thereby improving energy efficiency of the refrigerator.

As is apparent from the above description, unbalance in the amount of the refrigerant and unbalance in the amounts of heat generated from the hot pipes depending upon the operation modes of the refrigeration cycle are reduced, thereby improving energy efficiency of the refrigerator.

Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit thereof, the scope of which is defined in the claims and their equivalents. 

1. A refrigerator comprising a compressor, a condenser, a first circulation channel to cool a refrigerating chamber, a second circulation channel to cool a freezing chamber, and a channel switching valve to perform switching between the circulation channels, wherein a first hot pipe on a freezing chamber side; a second hot pipe on a refrigerating chamber side, wherein the first hot pipe is connected to the condenser and an inlet of the channel switching valve, and the second hot pipe is connected to an outlet of the channel switching valve.
 2. The refrigerator according to claim 1, wherein the second circulation channel is connected to another outlet of the channel switching valve, and the second circulation channel is connected to the compressor via a second expansion device and a second evaporator on the freezing chamber side.
 3. The refrigerator according to claim 1, wherein the first circulation channel is connected to a second evaporator on the freezing chamber side and the compressor via the second hot pipe, a first expansion device, a first evaporator on the refrigerating chamber side, and a third expansion device in a series.
 4. The refrigerator according to claim 1, wherein the first circulation channel is connected to a first evaporator on the refrigerating chamber side and the compressor via the second hot pipe and a first expansion device.
 5. The refrigerator according to claim 1, wherein the channel switching valve comprises a three-way valve having one inlet connected to an outlet of the first hot pipe and two outlets connected respectively to the first circulation channel and the second circulation channel.
 6. A refrigerator comprising a compressor, a condenser, a hot pipe, and a controller to control a first operation mode to cool a refrigerating chamber and a second operation mode to cool a freezing chamber, wherein the hot pipe comprises a first hot pipe on a freezing chamber side and a second hot pipe on a refrigerating chamber side, and the controller controls a refrigerant channel such that a refrigerant discharged from the condenser cools the freezing chamber via the first hot pipe and returns to the compressor during an operation in the second operation mode.
 7. The refrigerator according to claim 6, wherein the controller controls a refrigerant channel such that the refrigerant flows to the first hot pipe and the second hot pipe during an operation in the first operation mode.
 8. The refrigerator according to claim 6, wherein the controller controls a refrigerant channel such that the refrigerant discharged from the condenser cools the refrigerating chamber and the freezing chamber via the first hot pipe and the second hot pipe and returns to the compressor during an operation in the first operation mode.
 9. The refrigerator according to claim 6, wherein the controller controls a refrigerant channel such that the refrigerant discharged from the condenser cools the refrigerating chamber via the first hot pipe and the second hot pipe and returns to the compressor during an operation in the first operation mode.
 10. An operation control method of a refrigerator comprising a compressor, a condenser, a first hot pipe on a freezing chamber side, a second hot pipe on a refrigerating chamber side, a refrigerating chamber, and a freezing chamber, comprising: determining whether the refrigerating chamber or the freezing chamber is to be cooled; and controlling a refrigerant discharged from the condenser to cool the freezing chamber via the first hot pipe upon determining that the freezing chamber is to be cooled.
 11. The operation control method according to claim 10, further comprising controlling the refrigerant discharged from the condenser to cool the refrigerating chamber via the first hot pipe and the second hot pipe upon determining that the refrigerating chamber is to be cooled.
 12. The operation control method according to claim 11, further comprising controlling the refrigerant to cool the freezing chamber, after cooling the refrigerating chamber, and return to the compressor.
 13. The operation control method according to claim 11, further comprising controlling the refrigerant to return to the compressor after cooling the refrigerating chamber. 